Michael Breus, PhD: If you fall asleep before your head hits the pillow, that's not a good sign. That means you're sleep deprived, okay. If you fall asleep in less than 5 minutes on a regular basis, you probably need more sleep. If you fall asleep while driving, that's a big danger zone factor, a big red flag that you're going to want to understand a little bit more about. Driving a car, and operating a vehicle, while it may seem very rote, and may seem very easy to do if you notice yourself moving over lanes, not being able to stay in the lane as you normally would, that's going to be a definite sign of sleep deprivation. If you're not thinking as clearly, you're not making the decisions that you would normally make as quickly, that's going to be a sign of sleep deprivation. And, just overall movement, Uh, your reaction time slows down with sleep deprivation, your cognition time slows down. Believe it or not, even your creativity slows down with sleep deprivation. So, if you're at work, and you're trying to come up with a problem or a answer to a big problem, or trying to understand what's going on, and you're just not clicking, you're not finding the words, you're not doing the right thing or what you would normally do, it could be a sign of sleep deprivation.